Scheduling of Multiproducts with Limited Resources in an UPS (Uninterruptible Power Supply)

Scheduling procedures in an Uninterruptiple Power Supply (UPS) testing facility were investigated. It was determined that the facility was experiencing an inordinate number of missed product due dates. An analytical scheduling model was developed. However, due to a unique shift organization the computational complexity of the model overshadowed its usefulness and a reduced formulation was developed. The reduced scheduling formulation when used with an iterative approach, produced acceptable feasible solutions. It was also determined that due to the multiproduct nature of the industry, test facility capacity was not considered for specific product mixes. An analytical capacity model was developed to be used in conjunction with a heuristic to estimate capacity. Again, the computational complexity of the model was large and the determination was made to use a simulation approach. An operational tool for the test facility manager was developed in the form of a sequential simulation as an aid in scheduling and determining capacity and resource restrictions.